The Experimental Study Of Sutureless And Stentless Heterogeneity Aorta Biovalve

Stentless aortic bioprosthetic valve has been accepted by more and more cardiac surgery doctors for its transalvulas blood as laminar flow,lower transalvulas pressure gradient and larger effective valvular orifices area,and it particularly be applicable to old patients who have small aortic valve ring.However stentless aortic bioprosthetic valve have obvious disadvantages such as long time operation and aortic blood interruption,higher operation skills,higher incidence rate of valvular insufficiency and parabasilar leak because of inappropriate suture technique.Therefore,we devise a new sutureless and stentless hetero- geneity aorta biovalve;Then the new type valve will be evaluated by in vitro research and the pulse duplicate research through measure and contrast its function.The result will be referrence for inserting new valve to in vivo.AIM:1.To devise a new sutureless and stentless heterogeneity aorta biovalve;2.To research and test function of the new type valve in vitro.METHODS: 1.Choosing NiTi shape memeory alloy as a support material,through braiding and carving to manufacture new type stent and make sure its phase-transition temperature range 34 -42℃.2.Cuting fresh pig aorta valve,after anti-calcification handle step using 7-0 operation suture to take the valve to sew up to the Stent.Dacron will be reveted outside the NiTi shape memeory alloy stent.Then Using the liquid nitrogen to preserve the new valve;3.Set up heart model to insert into new valve, naked eye and Color Doppler ultrasound heart to observate valve closure, coronary blood flow and parabasilar leak.4. 25# valve were tested by TH-1200 H.V. Prosthesis Pulsatile Flow Tester in vitro,which was compared with 25# Mechanical valve.Mean transvalvular pressure gradient(MTPG),Effective orifice area(EOA) and Regurgitant fraction (RF) were tested.RESULTS:1.Devise and manufacture method of sutureless and stentless hetero- geneity aorta biovalve have reached the criterion of China about artificial heart valve proshtesis;2. New sutureless and stentless heterogeneity aorta biovalve can really simplify surgical operation process into the process, cut down operation difficulty, and can complete to cut off pathological changes valve and through naked eye and Color Doppler ultrasound heart we can observate the vlave have a tight closure, less parabasilar leak and have a outstanding coronary blood flow.3. MTPG of sutureless and stentless heterogeneity aorta biovalve under 3(3,4,5L/min)stimulant cardiac outputs were 4.215±0.220,5.168±0.367,6.158±0.487mmHg.EOA of sutureless and stentless hetero- geneity aorta biovalve 1.998±0.186,2.325±0.387,3.184±0.241cm2; RF of sutureless and stentless heterogeneity aorta biovalve 5.331±0.284,4.984±0.521,3.609±0.264% ,and all of them have reached the criterion of China about artificial heart valve proshtesis.CONCLUSION:1.The new type valve inheritted the excellent blood dynamics of biovalve, lower transalvulas pressure gradient, without anticoagulation etc. advantage, and simplified surgical operation.2. MTPG,EOA and RF of sutureless and stentless heterogeneity aorta biovalve have reached the criterion of China about artificial heart valve prosthesis .hydrodyamical characteristics under pulstile flow in vitro of the new artificial heart valve is superior to those of mechanical valve.This work is finical supported by Fujian Provincial Department of Science and Technology Foundation(2007J0109)...